Visualization of auto-ignition and pressure wave during knocking in a hydrogen spark-ignition engine

Nobuyuki Kawahara, Eiji Tomita

Research output: Contribution to journalArticlepeer-review

101 Citations (Scopus)


Visualizations of auto-ignition inside the end-gas region due to flame propagation and pressure waves that occur during knocking were carried out in a hydrogen spark-ignition engine using a high-speed camera. Our results demonstrated that auto-ignition in an end-gas region that was compressed by the propagating flame front could be visualized using the high-speed color camera. A large amount of unburned mixture caused by the auto-ignited kernel explosion generated the strong pressure waves. Strong pressure wave oscillations induced by the initial auto-ignition could be visualized using a video camera with a speed of 250 kframes/s. The auto-ignition and pressure waves caused the thermal boundary layer to breakdown near the cylinder wall and piston head, therefore combustion of the lubricant oil grease was visible inside burned gas region. This auto-ignition and pressure waves may result in damage to the cylinder wall and piston head during engine knocking.

Original languageEnglish
Pages (from-to)3156-3163
Number of pages8
JournalInternational Journal of Hydrogen Energy
Issue number7
Publication statusPublished - Apr 2009


  • Auto-ignition
  • Engine knock
  • Hydrogen spark-ignition engine
  • Pressure wave
  • Spectrum analysis

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology


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